Korede is a careful, competent nurse in Lagos, the responsible sister who keeps her head down and her surfaces clean. Her younger sister Ayoola is beautiful, charming, and adored by everyone she meets — and she has a habit of killing her boyfriends. Each time, Ayoola calls Korede, insists it was self-defence, and Korede arrives with bleach and a level head to make the bodies and the evidence disappear.
The arrangement holds until Ayoola sets her sights on Tade, a kind doctor at Korede's hospital whom Korede has quietly loved for years. Forced to choose between protecting her sister and warning the man she wants, Korede finds the careful order of her life beginning to crack, while the shadow of the sisters' abusive late father falls over everything they do.
Oyinkan Braithwaite's debut is a sharp, darkly comic thriller told in short, propulsive chapters. Set against a vivid Lagos backdrop, My Sister, the Serial Killer is less a whodunit than a study of loyalty, envy, and the impossible pull of family — funny and unsettling in equal measure.